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Faculty Publications

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Articles 31 - 60 of 235

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Resolution Of Physics And Deep Learning-Based Protein Engineering Filters: A Case Study With A Lipase For Industrial Substrate Hydrolysis, Spencer Gardiner, Peter Dollinger, Filip Kovacic, Jörge Pietruszka, Daniel Ess, Karl-Erich Jaeger, Gunnar F. Schröder, Dennis Della Corte Sep 2025

Resolution Of Physics And Deep Learning-Based Protein Engineering Filters: A Case Study With A Lipase For Industrial Substrate Hydrolysis, Spencer Gardiner, Peter Dollinger, Filip Kovacic, Jörge Pietruszka, Daniel Ess, Karl-Erich Jaeger, Gunnar F. Schröder, Dennis Della Corte

Faculty Publications

Computational enzyme design remains a powerful yet imperfect tool for optimizing biocatalysts, especially when targeting non-natural substrates. Using design tools we investigated Pseudomonas aeruginosa LipA, a lipase with a flexible lid domain crucial for substrate binding and turnover, aiming to enhance its hydrolysis of the industrially relevant substrate Roche ester. We generated an initial set of single-point mutations based on structural proximity to the active site and evaluated their effects using a computational pipeline integrating molecular dynamics (MD) simulations, density functional theory (DFT) calculations, and ensemble-based energy scoring. While we identified several active variants, attempts to rank them by activity …


Binding Of A [2fe-2s] Cluster Drives Dimerization Of Ferric Uptake Regulator (Fur) In Escherichia Coli, Fatemeh Najafi, Aidan G. Purcell, Finbar H. Homes, Huangen Ding Sep 2025

Binding Of A [2fe-2s] Cluster Drives Dimerization Of Ferric Uptake Regulator (Fur) In Escherichia Coli, Fatemeh Najafi, Aidan G. Purcell, Finbar H. Homes, Huangen Ding

Faculty Publications

The ferric uptake regulator (Fur) is a global transcription factor that reversibly binds an iron-sulfur [2Fe-2S] cluster via the cysteine residues (site 3) in response to elevation of intracellular free Fe content in Escherichia coli. Here, we report that when E. coli Fur is expressed in E. coli cells grown in M9 medium supplemented with Fe or zinc (Zn), purified Fur binds a [2Fe-2S] cluster or Zn(II), respectively. While apo-form Fur is a monomer and has no DNA-binding activity, both the [2Fe-2S] cluster-bound Fur and the Zn(II)-bound Fur are homodimers and have a similar binding activity for the DNA sequence …


Root Exudates: The Rhizospheric Frontier For Advancing Sustainable Plant Protection, Muhammad Rahil Afzal, Misbah Naz, Youbo Yu, Lisha Yan, Peiyi Wang, Janaki Mohotti, Gefei Hao, Jing-Jiang Zhou, Zhou Chen, Libo Zhang, Qian Wang Sep 2025

Root Exudates: The Rhizospheric Frontier For Advancing Sustainable Plant Protection, Muhammad Rahil Afzal, Misbah Naz, Youbo Yu, Lisha Yan, Peiyi Wang, Janaki Mohotti, Gefei Hao, Jing-Jiang Zhou, Zhou Chen, Libo Zhang, Qian Wang

Faculty Publications

Root exudates (REs), a diverse array of bioactive metabolites secreted by plant roots in response to environmental stimuli, serve as key mediators of rhizosphere ecology and plant defense responses, offering a promising avenue for sustainable pest management and eco-friendly plant protection. While earlier reviews primarily focus on root exudates in the context of general rhizosphere dynamics and plant-microbial interactions, critical knowledge gaps persist in REs-plant-pest tripartite interactions, the mechanistic basis of REs-mediated plant defense, and their practical integration with integrated pest management (IPM) frameworks. This review provides a synthesis of the latest literature on the biochemical diversity and functions of …


Growth Of Cylindrical Micelles And Their Use To Prepare Porous Materials With Tailored Dimensions And Alignment, Mengxue Zhang, Xiaomeng Li, Chuanbing Tang, Morgan Stefik Aug 2025

Growth Of Cylindrical Micelles And Their Use To Prepare Porous Materials With Tailored Dimensions And Alignment, Mengxue Zhang, Xiaomeng Li, Chuanbing Tang, Morgan Stefik

Faculty Publications

Materials with cylindrical pores are optimal for electrochemical devices and filtration due to their straight paths with minimal tortuosity when aligned. Polymer templates have led to many individual cylindrical architectures however the independent tailoring of pore and wall dimensions has remained elusive. Here short cylindrical micelle templates (PEO-b-PS) with glassy cores enabled the fabrication of sample series with constant cylindrical pore diameter (∼63 nm) and tailored wall thickness (TiO2, ∼45–100 nm). This ShortCyl series (aspect ratio 4.25) had modest alignment that was attributed to the low free-energy cost for misalignment. Though the plasticized micelles (DCM present) …


Non-Spectator Behavior Of A Neutral Phosphine Ligand Driven By A Redox-Active Boron Cluster, Jared R. Riffle, Cash L. Jowers, Sarah Luna, Mark D. Smith, Dmitry V. Peryshkov Jul 2025

Non-Spectator Behavior Of A Neutral Phosphine Ligand Driven By A Redox-Active Boron Cluster, Jared R. Riffle, Cash L. Jowers, Sarah Luna, Mark D. Smith, Dmitry V. Peryshkov

Faculty Publications

A new concept of ligand ambiphilicity that relies on the redox behavior of the indirectly coordinated boron cluster scaffold instead of the direct involvement of a single center in a ligand is introduced. A copper(I) complex of a carboranyl-based triphosphine, [tBuP-closo-{C2B10}-PhP-closo-{C2B10}-tBuP]CuPF6, in acetonitrile solution coordinates an exogenous X− anion (X− = Cl− or N3−) at the phosphorus center of the ligand and not at the cationic metal site to form [tBuP(X)-nido-{C2B …


Purification Of Uranium Tetrafluoride Using Ammonium Bifluoride, Kyle R. Foster, Juliano Schorne-Pinto, Ronald E. Booth, Annabelle Husek, Mina Aziziha, Hunter B. Tisdale, Bernie W.N. Fitzpatrick, Hans Conrad Zur Loye, Markus H.A. Piro, Theodore M. Besmann Jul 2025

Purification Of Uranium Tetrafluoride Using Ammonium Bifluoride, Kyle R. Foster, Juliano Schorne-Pinto, Ronald E. Booth, Annabelle Husek, Mina Aziziha, Hunter B. Tisdale, Bernie W.N. Fitzpatrick, Hans Conrad Zur Loye, Markus H.A. Piro, Theodore M. Besmann

Faculty Publications

A method of purification for UF4 utilizing NH4HF2 was investigated to remove oxygen and hydrate impurities from the salt. The original salt exhibited a melting point at 915–920 °C, which corresponds to the eutectic temperature of the UF4-UO2 system, showing clear signs of oxygen contamination. To purify the salt, an air-tight reaction vessel inside an argon glovebox was used to react UF4/NH4HF2 mixtures at elevated temperatures under a continuous flow of inert gas. The process yielded a significantly purer UF4 salt as confirmed via inert gas fusion, X-ray diffraction, differential scanning calorimetry and inductively coupled plasma-optical …


Crystal Growth, Thermal, Optical, Magnetic And Electrochemical Properties Of Mo2Ta2O11, Md Abdullah Al Muhit, Alevtina A. Maksimova, Sean C. Wechsler, Habiba Binte Kashem, Gopabandhu Panigrahi, Gregory Morrison, Morgan Stefik, Hans Conrad Zur Loye Jul 2025

Crystal Growth, Thermal, Optical, Magnetic And Electrochemical Properties Of Mo2Ta2O11, Md Abdullah Al Muhit, Alevtina A. Maksimova, Sean C. Wechsler, Habiba Binte Kashem, Gopabandhu Panigrahi, Gregory Morrison, Morgan Stefik, Hans Conrad Zur Loye

Faculty Publications

Single crystals of the transition metal oxide Mo2Ta2O11 were grown for the first time using molten flux synthesis. The compound crystalizes in the trigonal space group R 3‾m (no. 166) with lattice parameters a = b = 5.6267(1) Å and c = 25.1424(6) Å and a unit cell volume of 689.36(3) Å3. The structure of Mo2Ta2O11 is composed of alternating layers of TaO6 octahedra and MoO4 tetrahedra connected via corner-sharing. CaH2 was used to achieve a partial low temperature reduction of Mo2Ta2O11. The electrochemical lithiation of polycrystalline Mo2Ta2O11 was also investigated for the first time. Mo2Ta2O11 underwent a …


Photo-Crosslinked Persistent Micelle Templates With Near Universal Solvent Compatibility, Coby S. Collins, Mengxue Zhang, Cj Strurgill, Christian X. Ruff, Bryce Melton, Morgan Stefik Jun 2025

Photo-Crosslinked Persistent Micelle Templates With Near Universal Solvent Compatibility, Coby S. Collins, Mengxue Zhang, Cj Strurgill, Christian X. Ruff, Bryce Melton, Morgan Stefik

Faculty Publications

The controlled preparation of porous nanomaterials from block polymer templates is important for diverse applications from energy devices to optical coatings and sorbents. The architectural dimensions determine the overall performance for many of these applications, however the independent control of these dimensions has remained limited to a narrow range of solvent conditions for kinetically trapped (“persistent”) micelle templates. Polymers with a photo-reactive chemistry are shown to enable cross-linked micelle templates that universally remain persistent under diverse solvent conditions. Specifically, poly(poly(ethylene glycol methacrylate))-b-poly(butyl methacrylate-co-coumarin methacrylate) (OBC) was prepared by RAFT polymerization and the resulting micelles were crosslinked …


Human Gut Commensal Alistipes Timonensis Modulates The Host Lipidome And Delivers Anti-Inflammatory Outer Membrane Vesicles To Suppress Colitis In An Il10-Deficient Mouse Model, Ethan Older, Mary K. Mitchell, Andrew Campbell, Xiaoying Lian, Michael Madden, Yuzhen Wang, Lauren E. Van De Wal, Thelma Zaw, Brandon N. Vanderveen, Rodney Tatum, E. Angela Murphy, Yan-Hua Chen, Daping Fang, Melissa Ellermann, Jie Li Jun 2025

Human Gut Commensal Alistipes Timonensis Modulates The Host Lipidome And Delivers Anti-Inflammatory Outer Membrane Vesicles To Suppress Colitis In An Il10-Deficient Mouse Model, Ethan Older, Mary K. Mitchell, Andrew Campbell, Xiaoying Lian, Michael Madden, Yuzhen Wang, Lauren E. Van De Wal, Thelma Zaw, Brandon N. Vanderveen, Rodney Tatum, E. Angela Murphy, Yan-Hua Chen, Daping Fang, Melissa Ellermann, Jie Li

Faculty Publications

Correlative studies have linked human gut microbes to specific health conditions. Alistipes is one such microbial genus negatively linked to inflammatory bowel disease (IBD). However, the protective role of Alistipes in IBD is understudied, and the underlying molecular mechanisms remain unknown. In this study, colonization of Il10-deficient mice with Alistipes timonensis DSM 27924 delays colitis development. Colonization does not significantly alter the gut microbiome composition, but instead shifts the host plasma lipidome, increasing phosphatidic acids while decreasing triglycerides. Outer membrane vesicles (OMVs) derived from Alistipes are detected in the plasma of colonized mice, carrying potentially immunomodulatory metabolites into the …


A New Transition Metal Borate, Co6(B24O39(Oh)6(H2O) 6·2.21h2O, Synthesized Via A Mild Hydrothermal Synthesis, Alevtina Maksimova, Patrick Belt, Nilah Whitfield, Mark D. Smith, Gopabandhu Panigrahi, Gregory Morrison, Hans Conrad Zur Loye May 2025

A New Transition Metal Borate, Co6(B24O39(Oh)6(H2O) 6·2.21h2O, Synthesized Via A Mild Hydrothermal Synthesis, Alevtina Maksimova, Patrick Belt, Nilah Whitfield, Mark D. Smith, Gopabandhu Panigrahi, Gregory Morrison, Hans Conrad Zur Loye

Faculty Publications

A new transition metal borate hydrate, Co6B24O39(OH)6(H2O)6·2.21H2O, was synthesized via a mild hydrothermal method using boric acid as the melt. The compound crystallizes in the trigonal space group P 3‾ with lattice parameters a = b = 13.17840(10) Å, c = 12.3287(2) Å, and a unit cell volume of 1854.27(4) Å3 (Z = 2). This borate hydrate crystallizes in a new structure type comprised of layers containing [BO3] trigonal planar units and [BO4] tetrahedra that are linked by CoO6 and Co(OH)2(H2O)4 octahedra via corner-sharing. The …


Kinetic Control And Trapping In The Supramolecular Polymerization Of M-Terphenyl Bis-Urea Macrocycles, Sophya V. Garashchuk, Gamage Isuri P. Wijesekera, Isabella G. Rushton, Vaibhavi A. Samant, Fahidat A. Gbadamosi, Dr. Md Faizul Islam, Sophya V. Garashchuk, Prof. Dr. Linda S. Shimizu Apr 2025

Kinetic Control And Trapping In The Supramolecular Polymerization Of M-Terphenyl Bis-Urea Macrocycles, Sophya V. Garashchuk, Gamage Isuri P. Wijesekera, Isabella G. Rushton, Vaibhavi A. Samant, Fahidat A. Gbadamosi, Dr. Md Faizul Islam, Sophya V. Garashchuk, Prof. Dr. Linda S. Shimizu

Faculty Publications

Herein, we examine pathway complexity in the supramolecular polymerization of a novel m-terphenyl bis-urea macrocycle. Designed to induce kinetically metastable states, the macrocycle‘s concentration-dependent aggregation was studied via 1H NMR and IR spectroscopy in THF and CHCl₃. Temperature-dependent UV-Vis spectroscopy in water/THF revealed a cooperative nucleation-growth mechanism, indicated by a shift in λmax to longer wavelengths upon cooling. Morphological studies using DLS, AFM, and SEM demonstrated fibrous aggregate formation. Thermal hysteresis observed in assembly-disassembly cycles indicated kinetically trapped species, with cooling governed by kinetic control and heating by thermodynamic processes. Deviations in ΔH values during cooling, compared to van′t …


Synthesis Of A Series Of Rare-Earth-Based Multi-Anion Chalcogenide Iodides Re3Si2SeXS8-XI (Re = La, Ce, Pr, And Nd) Using The Flux-Assisted Boron-Chalcogen Mixture Method, Gopabandhu Panigrahi, Habiba Binte Kashem, Gregory Morrison, Hans Conrad Zur Loye Mar 2025

Synthesis Of A Series Of Rare-Earth-Based Multi-Anion Chalcogenide Iodides Re3Si2SeXS8-XI (Re = La, Ce, Pr, And Nd) Using The Flux-Assisted Boron-Chalcogen Mixture Method, Gopabandhu Panigrahi, Habiba Binte Kashem, Gregory Morrison, Hans Conrad Zur Loye

Faculty Publications

Single crystals and polycrystalline powders of rare earth mixed chalcogenide iodides La3Si2Se1.21S6.79I, Ce3Si2Se1.39S6.61I, Pr3Si2Se1.22S6.78I, and Nd3Si2Se1.18S6.82I were prepared using the reactive flux-assisted boron-chalcogen mixture (BCM) method at 850 °C. All compounds crystallized in the monoclinic crystal system, space group C2/c (space group number 15). The series adopts the La3Si2O8Cl structure type, containing isolated SiQ4 tetrahedra connected by REQ8 (RE = La, Ce, Pr and Nd) polyhedra; this arrangement creates tunnels that are filled by I atoms. The partial substitution of S by Se was carried out to modulate the optical properties. Phase pure samples and uniform solid solutions were obtained …


Nanostructure Retention To 1100 °C In Soft-Templated Niobium Tungstates Using Dual-Carbon Strategy, Sean C. Wechsler, Alexander Gregg, Coby S. Collins, Santosh Kiran Balijepalli, Morgan Stefik Mar 2025

Nanostructure Retention To 1100 °C In Soft-Templated Niobium Tungstates Using Dual-Carbon Strategy, Sean C. Wechsler, Alexander Gregg, Coby S. Collins, Santosh Kiran Balijepalli, Morgan Stefik

Faculty Publications

Mesoporous metal oxides (MMOs) have diverse applications including energy storage, catalysis, and separation membranes. Block polymer structure directing agents enable the control of morphology and pore size, however preservation of the nanostructure is often limited to a narrow range of heat treatment temperatures which constrains the tailoring of defect chemistries. High temperature treatments typically lead to collapse of the porous structure as surface area is reduced during crystal growth. Here, using a mesoporous niobium tungstate it is shown that neither in situ carbon generation nor ex situ carbon infiltration alone enable preservation of the ordered mesostructure at temperatures high enough …


Associations Between Social Determinants Of Health And Mental Health Disorders Among U.S. Population: A Cross-Sectional Study, S. Tanarsuwongkul Jan 2025

Associations Between Social Determinants Of Health And Mental Health Disorders Among U.S. Population: A Cross-Sectional Study, S. Tanarsuwongkul

Faculty Publications

Aims

The impact of social determinants of health (SDOH) on mental health is increasingly realized. A comprehensive study examining the associations of SDOH with mental health disorders has yet to be accomplished. This study evaluated the associations between five domains of SDOH and the SDOH summary score and mental health disorders in the United States.

Methods

We analyzed data from a diverse group of participants enrolled in the All of Us research programme, a research programme to gather data from one million people living in the United States, in a cross-sectional design. The primary exposure was SDOH based on Healthy …


Durable Oxyfluoride Waste Forms For Salt Wastes From Molten Salt Reactors, Alevtina A. Maksimova, Jake W. Amoroso, Matthew Page, Gregory Morrison, Hans Conrad Zur Loye Jan 2025

Durable Oxyfluoride Waste Forms For Salt Wastes From Molten Salt Reactors, Alevtina A. Maksimova, Jake W. Amoroso, Matthew Page, Gregory Morrison, Hans Conrad Zur Loye

Faculty Publications

Molten salt reactors (MSRs) are promising technology to replace traditional light and heavy water reactors in the near future. Waste management for MSRs, however, remains a pressing concern that needs to be resolved prior to realizing deployment of MSRs. Specifically, the generated salt waste needs to be safely sequestered, a task made difficult by the high solubility of the salt waste that can cause the release of radionuclides into the environment. This work demonstrates a new approach to immobilize multiple fluoride salts into a single waste form by converting highly-soluble fluorides to durable and stable oxyfluorides. Notably, we report a …


Molten Flux Synthesis Of Plutonium (Iv) Silicates K2Pusi2O7 And Rb2Pusi6O15, Travis K. Deason, Gregory Morrison, Amir Mofrad, Jake Amoroso, David Diprete, Theodore M. Besmann, Shanna L. Estes, Hans Conrad Zur Loye Dec 2024

Molten Flux Synthesis Of Plutonium (Iv) Silicates K2Pusi2O7 And Rb2Pusi6O15, Travis K. Deason, Gregory Morrison, Amir Mofrad, Jake Amoroso, David Diprete, Theodore M. Besmann, Shanna L. Estes, Hans Conrad Zur Loye

Faculty Publications

Few plutonium containing silicates have been reported in the literature and only one other tetravalent plutonium silicate structure has been reported using the flux growth method. With the goal of understanding actinide incorporation into silicates, we describe herein two new plutonium (IV) silicates, Rb2PuSi6O15 and K2PuSi2O7, synthesized using a mixed alkali chloride/alkali fluoride flux growth. Both structures crystallize in the C2/c space group with lattice parameters a=24.2980(10) Å, b=7.1466(3) Å, c=17.2025(8) Å and 96.6560(10)° for Rb2PuSi6O15, and a=9.9478(2) Å, b=5.59820 (10) Å, c=13.1848(2) Å, and 105.7400(10)° for K2PuSi2O7. Comparisons to the synthesis of other reported alkali actinide silicates (Ce, U, …


Capacity-Weighted Figures-Of-Merit For Battery Transport Metrics, Cj Sturgill, Christopher Sutton, Julian Schwenzel, Morgan Stefik Dec 2024

Capacity-Weighted Figures-Of-Merit For Battery Transport Metrics, Cj Sturgill, Christopher Sutton, Julian Schwenzel, Morgan Stefik

Faculty Publications

New battery materials with improved transport are needed. Typical measurements yield widely varying voltage-dependent diffusivities and reporting practices are diverse. Some materials (e.g. first-order phase change) have most redox occur at a specific voltage and may be sufficiently represented by singular transport metrics. Many rapid intercalation materials, however, exhibit second-order phase transitions with redox over a broad voltage range. How should such cases be compared? The use of capacity-weighted average values is suggested where voltage-dependent metrics are consolidated into representative descriptors as figures-of-merit. Examples are elaborated where differential capacity (dQ/dV) is used to derive a …


Na2B12Si6Se18: A Novel B12-Cluster-Containing Quaternary Selenoborate Framework Material, Gopabandhu Panigrahi, Hunter B. Tisdale, Gregory Morrison, Hans Conrad Zur Loye Dec 2024

Na2B12Si6Se18: A Novel B12-Cluster-Containing Quaternary Selenoborate Framework Material, Gopabandhu Panigrahi, Hunter B. Tisdale, Gregory Morrison, Hans Conrad Zur Loye

Faculty Publications

We report the successful synthesis of the new quaternary, three-dimensional Na2B12Si6Se18 material using a solid-state synthesis route. This compound is characterized by a unique framework structure that features the rare icosahedral [B12]10+ cation which is connected via Si2Se6 polyhedral units into a 3D framework structure with Na+ ions located inside the channels. The Na2B12Si6Se18 compound crystallizes in the cubic crystal system in the space group Im, with lattice parameter a = 11.91110(10) Å and unit cell volume of 1689.88(4) Å3. …


Investigation Of Magnesium-Potassium Phosphates As Potential Nuclear Waste Form For The Immobilization Of Minor Actinides, Hans Conrad Zur Loye, Petr Vecernik, Monika Kiselova, Vlastislav Kašpar, Hana Korenkova, Vlastimil Miller, Petr Bezdicka, Jan Šubrt, Natalija Murafa, Volodymyr Shkuropatenko, Sergey Sayenko Dec 2024

Investigation Of Magnesium-Potassium Phosphates As Potential Nuclear Waste Form For The Immobilization Of Minor Actinides, Hans Conrad Zur Loye, Petr Vecernik, Monika Kiselova, Vlastislav Kašpar, Hana Korenkova, Vlastimil Miller, Petr Bezdicka, Jan Šubrt, Natalija Murafa, Volodymyr Shkuropatenko, Sergey Sayenko

Faculty Publications

Several recent studies have evaluated technologies of spent nuclear fuel processing specifically for solidifying transuranic (TRU) waste as a by-product of fission. Of the TRU group, plutonium and the minor actinides will be responsible for the bulk of the radiotoxicity and heat generation of spent nuclear fuel in the long term (300 to 20,000 years). In this study, we investigated magnesium potassium phosphate (MKP)-based compounds as host waste forms for the encapsulation of inactive trivalent Nd and Sm as analogues of the minor trivalent actinides, Am and Cm. Waste forms were fabricated under ambient atmospheric conditions by adding 5 wt.% …


Examination Of Photoinduced Radicals In Two Crystal Forms Of Triphenylamine Bis-Urea Macrocycles, Md Faizul Islam, Gamage Isuri P. Wijesekera, Anmon J. Sindt, Mark D. Smith, Linda S. Shimizu Oct 2024

Examination Of Photoinduced Radicals In Two Crystal Forms Of Triphenylamine Bis-Urea Macrocycles, Md Faizul Islam, Gamage Isuri P. Wijesekera, Anmon J. Sindt, Mark D. Smith, Linda S. Shimizu

Faculty Publications

This study probes two solvates of triphenylamine (TPA) bis-urea macrocycle 1 and their activated structures to evaluate their maximum photoinduced radicals (PIRs), the subsequent decay of the radicals, and their regeneration. The hierarchical assembly of TPAs shows promise in stabilizing less substituted derivatives, potentially expanding the utility of TPAs that lack stabilizing para-substituents. Single crystal structure analysis reveals that host 1 adopts a planar conformation with the two ureas pointing in opposite directions when dimethoxyethane (DME) is encapsulated within the channel. Whereas previously, 1 adopted a bowl-shaped conformation with the two ureas pointing in the same direction (syn …


Examination Of Photoinduced Radicals In Two Crystal Forms Of Triphenylamine Bis-Urea Macrocycles, Md Faizul Islam, Gamage Isuri P. Wijesekera, Ammon J. Sindt, Mark D. Smith, Linda S. Shimizu Oct 2024

Examination Of Photoinduced Radicals In Two Crystal Forms Of Triphenylamine Bis-Urea Macrocycles, Md Faizul Islam, Gamage Isuri P. Wijesekera, Ammon J. Sindt, Mark D. Smith, Linda S. Shimizu

Faculty Publications

This study probes two solvates of triphenylamine (TPA) bis-urea macrocycle 1 and their activated structures to evaluate their maximum photoinduced radicals (PIRs), the subsequent decay of the radicals, and their regeneration. The hierarchical assembly of TPAs shows promise in stabilizing less substituted derivatives, potentially expanding the utility of TPAs that lack stabilizing para-substituents. Single crystal structure analysis reveals that host 1 adopts a planar conformation with the two ureas pointing in opposite directions when dimethoxyethane (DME) is encapsulated within the channel. Whereas previously, 1 adopted a bowl-shaped conformation with the two ureas pointing in the same direction (syn …


Accurate Crystal Structure Prediction Of New 2d Hybrid Organic–Inorganic Perovskites, Nima Karimitari, William J. Baldwin, Evan W. Muller, Zachary J.L. Bare, W. Joshua Kennedy, Gábor Csányi, Christopher Sutton Sep 2024

Accurate Crystal Structure Prediction Of New 2d Hybrid Organic–Inorganic Perovskites, Nima Karimitari, William J. Baldwin, Evan W. Muller, Zachary J.L. Bare, W. Joshua Kennedy, Gábor Csányi, Christopher Sutton

Faculty Publications

Low-dimensional hybrid organic–inorganic perovskites (HOIPs) are promising electronically active materials for light absorption and emission. The design space of HOIPs is extremely large, as a variety of organic cations can be combined with different inorganic frameworks. This not only allows for tunable electronic and mechanical properties but also necessitates the development of new tools for in silico high throughput analysis of candidate materials. In this work, we present an accurate, efficient, and widely applicable machine learning interatomic potential (MLIP) trained on 86 diverse experimentally reported HOIP materials. This MLIP was tested on 73 experimentally reported perovskite compositions and achieves a …


Improvement Of Single-Crystal Structures Of Very Heavy Element Compounds By Refining Anomalous Dispersion Parameters, Florian Meurer, Gregory Morrison, Birgit Hischa, Hans Conrad Zur Loye, Christoph Hennig, Michael Bodensteiner Aug 2024

Improvement Of Single-Crystal Structures Of Very Heavy Element Compounds By Refining Anomalous Dispersion Parameters, Florian Meurer, Gregory Morrison, Birgit Hischa, Hans Conrad Zur Loye, Christoph Hennig, Michael Bodensteiner

Faculty Publications

Refining the anomalous dispersion parameters of the four uranium compounds NaUF5, NaU2F9, Cs2(UO2)TiO4, and Cs2(UO2)Ti2O6 gave insights into the crystallographic model improvement of very heavy atoms. We found that the values for the dispersive and absorptive parts, f′ and f″, closely followed the X-ray absorption spectra on their L3, L2, and L1 edges. The obtained values are sensitive to the chemical environment at each crystallographically independent position. An incorrect treatment of the anomalous dispersion correction can lead to a wrong crystallographic model. The above-mentioned, already published structures were improved by this process. General guidelines were given for the crystal structure …


Incorporating Oxygen Isotopes Of Oxidized Reactive Nitrogen In The Regional Atmospheric Chemistry Mechanism, Version 2 (Icoin-Racm2), Wendell W. Walter, Masayuki Takeuchi, Nga L. Ng, Meredith G. Hastings Jun 2024

Incorporating Oxygen Isotopes Of Oxidized Reactive Nitrogen In The Regional Atmospheric Chemistry Mechanism, Version 2 (Icoin-Racm2), Wendell W. Walter, Masayuki Takeuchi, Nga L. Ng, Meredith G. Hastings

Faculty Publications

The oxygen isotope anomaly (Δ17O = δ17O − 0.52 × δ18O > 0) has proven to be a robust tool for probing photochemical cycling and atmospheric formation pathways of oxidized reactive nitrogen (NOy). Several studies have developed modeling techniques to implicitly model Δ17O of NOy molecules based on numerous assumptions that may not always be valid. Thus, these models may be oversimplified and limit our ability to compare model Δ17O values of NOy with observations. In this work, we introduce a novel method for explicitly tracking Δ …


Development Of An Experimentally Validated Computational Fluid Dynamics Model For A Pbi Membrane-Based Anhydrous Hcl Electrolyzer, Kris Likit-Anurak, Hunter R. Teel, Ishwor Karki, Ben I. Howard, Brian C. Benicewicz, Sirivatch Shimpalee, Benjamin H. Meekins May 2024

Development Of An Experimentally Validated Computational Fluid Dynamics Model For A Pbi Membrane-Based Anhydrous Hcl Electrolyzer, Kris Likit-Anurak, Hunter R. Teel, Ishwor Karki, Ben I. Howard, Brian C. Benicewicz, Sirivatch Shimpalee, Benjamin H. Meekins

Faculty Publications

We report the development of an experimentally-validated computational fluid dynamics (CFD) model for simulation of an anhydrous HCl electrolyzer. The experimental data from 3 membrane variants was used to provide kinetic and membrane parameters for the model. The model not only accurately simulates overall electrolyzer performance, but it also provides key insights into the transport phenomena within the electrolyzer. The model allows simulation of experimental parameters like high HCl flowrates and increased cell pressure that pose a high safety risk to researchers. The model shows hotspots in the temperature distribution that will need to be addressed by flow field modification …


Incorporating Solvent Effects In Dft: Insights From Cation Exchange In Faujasites, An T. Ta, Ayoub Daouli, R. Seaton Ullberg, Eric Fonseca, Vanessa Proust, Agnès Grandjean, Richard G. Hennig, Hans Conrad Zur Loye, Michael Badawi, Simon R. Phillpot May 2024

Incorporating Solvent Effects In Dft: Insights From Cation Exchange In Faujasites, An T. Ta, Ayoub Daouli, R. Seaton Ullberg, Eric Fonseca, Vanessa Proust, Agnès Grandjean, Richard G. Hennig, Hans Conrad Zur Loye, Michael Badawi, Simon R. Phillpot

Faculty Publications

Zeolites are versatile materials renowned for their extra-framework cation exchange capabilities, with applications spanning diverse fields, including nuclear waste treatment. While detailed experimental characterization offers valuable insight, density functional theory (DFT) proves particularly adept at investigating ion exchange in zeolites, owing to its atomic and electronic resolution. However, the prevalent occurrence of zeolitic ion exchange in aqueous environments poses a challenge to conventional DFT modeling, traditionally conducted in a vacuum. This study seeks to enhance zeolite modeling by systematically evaluating predictive differences across varying degrees of aqueous solvent inclusion. Specifically focusing on monovalent cation exchange in Na-X zeolites, we explore …


Structural Homology Of Mite Profilins To Plant Profilins Is Not Indicative Of Allergic Cross-Reactivity, Andrea O'Malley, Sahana Sankaran, Avery Carriuolo, Kriti Khatri, Krzysztof Kowal, Maksymilian Chruszcz Ph.D. Apr 2024

Structural Homology Of Mite Profilins To Plant Profilins Is Not Indicative Of Allergic Cross-Reactivity, Andrea O'Malley, Sahana Sankaran, Avery Carriuolo, Kriti Khatri, Krzysztof Kowal, Maksymilian Chruszcz Ph.D.

Faculty Publications

Structural and allergenic characterization of mite profilins has not been previously pursued to a similar extent as plant profilins. Here, we describe structures of profilins originating from Tyrophagus putrescentiae (registered allergen Tyr p 36.0101) and Dermatophagoides pteronyssinus (here termed Der p profilin), which are the first structures of profilins from Arachnida. Additionally, the thermal stabilities of mite and plant profilins are compared, suggesting that the high number of cysteine residues in mite profilins may play a role in their increased stability. We also examine the cross-reactivity of plant and mite profilins as well as investigate the relevance of these profilins …


Broad-Spectrum Lignin-Based Adhesives Using Thiol–Silyl Ether Crosslinkers, Yishayah Bension, Siteng Zhang, Tristan Menninger, Ting Ge, Chuanbing Tang Apr 2024

Broad-Spectrum Lignin-Based Adhesives Using Thiol–Silyl Ether Crosslinkers, Yishayah Bension, Siteng Zhang, Tristan Menninger, Ting Ge, Chuanbing Tang

Faculty Publications

Lignin is a renewable feedstock that is abundant and inexpensive but still presents challenges for its valorization. In this work, we converted functionalized lignin into broad-spectrum adhesives using thiol–silyl ether crosslinkers. The curing behavior of adhesives was investigated via rheology of their resin forms. These materials exhibit good adhesion on diverse substrates, including wood, glass, steel, aluminium, carbon fiber, and different plastics, with the most adhesion strength in the range of 1–3 MPa. These adhesives were also explored for applications, ranging from wet conditions to different mechanically responsive materials. The mechanism of adhesion was further examined to understand the bonding …


Unimer Suppression Enables Supersaturated Homopolymer Swollen Micelles With Long-Term Stability After Glassy Entrapment, Eric R. Williams, Christian X. Ruff, Morgan Stefik Feb 2024

Unimer Suppression Enables Supersaturated Homopolymer Swollen Micelles With Long-Term Stability After Glassy Entrapment, Eric R. Williams, Christian X. Ruff, Morgan Stefik

Faculty Publications

Micelle sizes are critical for a range of applications where the simple ability to adjust and lock in specific stable sizes has remained largely elusive. While micelle swelling agents are well-known, their dynamic re-equilibration in solution implies limited stability. Here, a non-equilibrium processing sequence is studied where supersaturated homopolymer swelling is combined with glassy-core (“persistent”) micelles. This path-dependent process was found to sensitively depend on unimer concentration as revealed by DLS, SAXS, and TEM analysis. Here, lower-selectivity solvent combinations led to the formation of unimer-homopolymer aggregates and eventual precipitation, reminiscent of anomalous micellization. In contrast, higher-selectivity solvents enabled supersaturated homopolymer …


Unimer Suppression Enables Supersaturated Homopolymer Swollen Micelles With Long-Term Stability After Glassy Entrapment, Eric R. Williams, Christian X. Ruff, Morgan Stefik Feb 2024

Unimer Suppression Enables Supersaturated Homopolymer Swollen Micelles With Long-Term Stability After Glassy Entrapment, Eric R. Williams, Christian X. Ruff, Morgan Stefik

Faculty Publications

Micelle sizes are critical for a range of applications where the simple ability to adjust and lock in specific stable sizes has remained largely elusive. While micelle swelling agents are well-known, their dynamic re-equilibration in solution implies limited stability. Here, a non-equilibrium processing sequence is studied where supersaturated homopolymer swelling is combined with glassy-core (“persistent”) micelles. This path-dependent process was found to sensitively depend on unimer concentration as revealed by DLS, SAXS, and TEM analysis. Here, lower-selectivity solvent combinations led to the formation of unimer-homopolymer aggregates and eventual precipitation, reminiscent of anomalous micellization. In contrast, higher-selectivity solvents enabled supersaturated homopolymer …